Hook-and-eye fastener

Abstract: A hook-and-eye fastener (1) comprises fastener members including a hook and an eye (10,30), each member having a pair of engaging prongs (15a,15b) projecting substantially perpendicularly therefrom, and retainers (20) adapted severally to immobilize the fastener members and intended to be disposed on the side of a fabric (110) opposite to the side thereof on which the fastener members (10) are set in place. Each of the retainers (20) has a pair of thin-wall parts (24a,24b) adapted to be pierced by the pair of engaging prongs (15a,15b) of the relevant fastener member (10) , and leading ends of the engaging prongs (15a,15b) of each fastener member are formed in the shape of a flat part lying in a plane substantially perpendicular to a direction of penetration of the engaging prongs (15a,15b) into the thin-wall parts (24a,24b) of the relevant retainer (20).

Description: The invention relates to a hook and to an eye for a hook-and-eye fastener each comprising a pair of engaging prongs projecting substantially perpendicularly therefrom; and a retainer adapted severally to immobilize the hook or eye, respectively, and intended to be disposed on the side of a fabric opposite to the side thereof on which the hook or eye, respectively, is set in place; the retainer having a pair of thin-wall parts adapted to be pierced by the pair of engaging prongs of the hook or eye, respectively. The conventional hook-and-eye fasteners, as disclosed in U.S. Pat. No. 4,639,983 issued to Fukuroi et al. on Feb. 3, 1987, comprise a recurved hook made of brass, an eye made of brass and adapted to have the hook caught thereon, and retainers made of brass, adapted severally to fix the hook and the eye, and disposed on the side of a fabric opposite to the side thereof on which the hook and the eye are seated. The hook and the eye are each provided integrally with a pair of engaging prongs adapted to be fixed in the relevant retainers. The retainers severally have formed therein a pair of through holes adapted to be inserted thereinto by the pair of engaging prongs. The fixation of the hook and the eye to the fabric is accomplished by positioning the retainers on the opposite side of the fabric, inserting the engaging prongs of the hook and the eye through the fabric into the through holes of the retainers, and then bending the engaging prongs inwardly toward each other thereby joining the hook and the eye infallibly to the respective retainers. Incidentally, the leading end parts of the engaging prongs are formed in a sharply pointed acute angle shape as indicated by a two-dot chain line in Fig. 4 so as to facilitate the penetration of the engaging prongs through the fabric. In the prior art hook-and-eye fastener described above, the insertion of the engaging prongs into the through holes of the retainers entails the problem that the engaging prongs having sharply pointed leading terminals force their way between adjacent component threads of the fabric while dragging the fabric into the through holes and leaving wrinkles behind in the fabric around the sites of insertion. Further, the insertion of the engaging prongs into the through holes poses the problem that the leading end parts of the engaging prongs catch hold of threads of the fabric while piercing the fabric, drag the threads in the longitudinal and lateral direction of the fabric in the parts of the insertion of the engaging prongs and, as a result, impart a distortion to the pattern of the fabric in the parts in which the drag of threads has taken place and gather longitudinal and lateral wrinkles in the affected parts of the fabric. For the purpose of restraining this phenomenon of the dragging of threads, hook-and-eye fasteners comprising a hook and an eye as described in the beginning of this description which have through holes in the retainers covered with a thin plate of aluminum as disclosed in published Japanese Utility Model Application. KOKAI (Early Publication) No. HEI 4-112,612 have been proposed to the art. In this case, when the engaging prongs are inserted into the through holes, the fabric is dragged into the through holes with difficulty because the thin plate holds the fabric in place. In this case, however, the separate thin plate covering the through holes is inevitably applied to the retainers. Thus, these hook-and-eye fasteners entail the problem that the number of component parts increases and the process of manufacture gains in complexity proportionately. Moreover, they still entail the problem that the sharply pointed leading end parts of the engaging prongs catch hold of threads of the fabric and drag them into the through holes. Similarly to those of the former version described above, these hook-and-eye fasteners tend to impart wrinkles to the fabric during the insertion of the engaging prongs. US-A-4 639 983 discloses a hook-and-eye fastener including a hook having at least a pair of prongs and a retainer which are attached by inwardly axially bent ends of the prongs. The leading ends of the prongs are shown to be of rounded form. It is an object of the present invention to provide a hook and an eye for a hook-and-eye fastener which attains the attachment of a hook and an eye across a fabric to their respective retainers without either entailing the dragging of threads or leaving wrinkles behind in the fabric after the attachment. This object is solved by providing a hook and an eye for a hook-and-eye fastener having the features of claim 1 and 7, respectively. Advantageous further embodiments are indicated in the dependent claims. As claimed a hook for a hook-and-eye fastener is provided, comprising: a pair of engaging prongs projecting substantially perpendicularly therefrom; and a retainer adapted to immobilize the hook and intended to be disposed on the side of a fabric opposite to the side thereof on which the hook is set in place. The retainer has a pair of thin-wall parts adapted to be pierced by the pair of engaging prongs of the hook. According to the invention leading ends of the engaging prongs of the hook are formed in the shape of a flat part lying in a plane substantially perpendicular to a direction of pene-tration of the engaging prongs into the thin-wall parts of the retainer. Further an eye for a hook-and-eye fastener as claimed comprises: a pair of engaging prongs projecting substantially perpendicularly therefrom; and a retainer adapted to immobilize the eye and intended to be disposed on the side of a fabric opposite to the side thereof on which the eye is set in place. The retainer has a pair of thin-wall parts adapted to be pierced by the pair of engaging prongs of the eye. According to the invention leading ends of the engaging prongs of the eye are formed in the shape of a flat part lying in a plane substantially perpendicular to a direction of penetration of the engaging prongs into the thin-wall parts of the retainer. According to the present invention, there is also provided a hook-and-eye fastener comprising: fastener members comprising a hook and an eye, each member having a pair of engaging prongs projecting substantially perpendicularly therefrom; and retainers adapted to immobilize the fastener members and intended to be disposed on the side of a fabric opposite to the side therof an which the fastener members are set in place. In the hook-and-eye fastener according to the present invention each of the retainers has a pair of thin-wall parts adapted to be pierced by the pair of engaging prongs of the relevant fastener member, and the leading ends of the engaging prongs of each fastener member are formed in the shape of a flat part lying in a plane substantially perpendicular to a direction of penetration of the engaging prongs into the thin-wall parts of the relevant retainer. In the attachment of the hook-and-eye fastener according to the present invention to a fabric, the engaging prongs of each fastener member are so positioned that the flat parts at the leading ends thereof remain in surface contact across the fabric with the thin-wall parts of the relevant retainer and the engaging prongs in the state mentioned above are pushed to pierce the thin-wall parts of the retainer. Owing to this arrangement, the fabric is cut in the plane or line of contact between the flat parts at leading ends of the engaging prongs and the thin-wall parts of the retainer when the engaging prongs collide against and pierce the thin-wall parts of the retainer. Subsequently, when the engaging prongs are farther inserted into the through holes consequently formed in the thin-wall parts of the retainer, they neither catch hold of threads of the fabric and drag them into the through holes nor gather wrinkles in the fabric around the sites of their fixation. In carrying out the present invention in one preferred mode, to easily form the thin-wall parts in the retainer and allow the leading ends of the engaging prongs of each fastener member to pierce the thin-wall parts of the relevant retainer, the fastener members are made of a metal, preferably brass, and the retainers are made of aluminum or aluminum alloy. Preferably each of the engaging prongs of the fastener members has a free end part configured as a truncated wedge whose leading end face is formed in a flat surface substantially perpendicular to a longitudinal direction thereof. Other objects, features, and advantages of the invention will become apparent from the following description taken together with the drawings, in which: Fig. 1 is a perspective view illustrating one embodiment of a hook and a retainer of the hook-and-eye fastener according to the present invention in the state ready for fixation; Fig. 2 is a perspective view illustrating the hook-and-eye fastener of the same embodiment in the state of actual use; Fig. 3 is a partially sectioned side view illustrating the hook and the retainer of the hook-and-eye fastener of the same embodiment in the state ready for attachment to a fabric; Fig. 4 is an enlarged fragmentary side view showing an engaging prong in the hook of the hook-and-eye fastener of the same embodiment; Fig. 5 is a cross sectional view illustrating an assembly of the hook and the retainer attached to the fabric; and Fig. 6 is a perspective view illustrating one embodiment of an eye and a retainer of the hook-and-eye fastener according to the present invention. Fig. 1 through Fig. 6 show a hook-and-eye fastener which is intended to be used in an opening part as in trousers or a skirt 100. As shown in Fig. 2, the hook-and-eye fastener 1 comprises a recurved hook 10 made of brass and an eye or companion loop 30 made of brass and adapted to keep hold of the hook 10. On the side of a fabric 110 such as of trousers opposite to the side thereof to which the hook 10 and the eye 30 are attached, retainers 20 and 40 made of aluminum (inclusive of aluminum alloy) and adapted to fix the hook 10 and the eye 30 respectively are disposed, as shown in Fig. 1 and Fig. 6. As shown in Fig. 1, the hook 10 has a one-piece body including an upper locking tongue 11, a lower base 13 lying substantially parallel to the locking tongue 11, and an intermediate arcuate portion 12 extending between the locking tongue 11 and the base 13 so as to define therebetween an eye-receiving channel 14 for receiving an upper plate 31 of the eye 30. The base 13 has on opposite lateral edges thereof a pair of engaging prongs 15a and 15b projecting parallel and substantially perpendicularly therefrom in a direction away from the locking tongue 11. Each of the engaging prongs 15a and 15b has a free end part configured as a truncated wedge. The leading end of each engaging prong 15a or 15b is formed in the shape of a flat part 16a or 16b lying in a plane substantially perpendicular to a direction of penetration of the engaging prongs 15a and 15b into the thin-wall parts 24a and 24b of the retainer 20. That is, the leading end face of each engaging prongs 15a or 15b is formed in a flat surface substantially perpendicular to a longitudinal direction thereof, as best shown in Fig. 4. The retainer 20 has a central raised portion 21 extending throughout the width of the retainer, an upwardly bent rear portion 22 extending rearwardly from the central raised portion 21, and a flat front portion 23 extending forwardly from the central raised portion 21. The central raised portion 21 serves as a support for the base 13 of the hook 10. The retainer 20 has in the central raised portion 21 thereof a pair of thin-wall parts 24a and 24b to be pierced respectively by the pair of engaging prongs 15a and 15b of the hook 10. Therefore, the distance between the thin-wall parts 24a and 24b is substantially corresponding to that between the engaging prongs 15a and 15b of the hook 10. These thin-wall parts 24a and 24b are formed by pressing two prescribed parts of the central raised portion 21 of the retainer 20 to a thickness small enough to be pierced by the flat parts 16a and 16b at the leading ends of the engaging prongs 15a and 15b when these flat parts 16a and 16b collide against and pierce the thin-wall parts 24a and 24b. As best shown in Fig. 3, each thin-wall part 24a or 24b of the retainer 20 has an upper surface lying flush with an upper surface of the retainer and a lower concave surface. As shown in Fig. 6, the eye 30 is likewise provided with a pair of engaging prongs 32a and 32b projecting substantially perpendicularly from opposite lateral edges of an upper plate 31. These engaging prongs 32a and 32b, similarly to those of the hook 10, have free end parts configured as a truncated wedge whose leading end face 33a or 33b is formed in a flat surface substantially perpendicular to a longitudinal direction thereof and are so disposed as to pierce the thin-wall parts 44a and 44b formed in the retainer 40 for the eye 30. The retainer 40 has a central raised portion 41 in which the pair of thin-wall parts 44a and 44b are formed and upwardly bent portions 42 and 43 extending from the both sides of the central raised portion 41. To attach the hook 10 of the hook-and-eye fastener 1 of this embodiment to the fabric 110, first the retainer 20 is set at a prescribed position on the side of the fabric 110 opposite to the side thereof on which the hook 10 is to be set in place. Then, the engaging prongs 15a and 15b of the hook 10 are pressed across the fabric 110 against the thin-wall parts 24a and 24b of the retainer 20 until the engaging prongs 15a and 15b completely pierce the thin-wall parts 24a and 24b. Thereafter, by means of a suitable punch-and-die unit (not shown), the engaging prongs 15a and 15b are bent inwardly toward each other on the reverse surface side of the retainer 20 to join the hook 10 to the retainer 20 infallibly, as shown in Fig. 5. The hook 10 and the retainer 20 thus attached together to the fabric 110 disposed therebetween constitute a hook engageable with the eye attached to another fabric. The attachment of the eye 30 of the hook-and-eye fastener 1 to the fabric 110 is carried out in the same manner as that of the hook 10 described above. When the engaging prongs 15a and 15b (or 32a and 32b) of the hook 10 (or eye 30) are on the verge of piercing the thin-wall parts 24a and 24b (or 44a and 44b) of the retainer 20 (or 40), the flat parts 16a and 16b (or 33a and 33b) at the leading ends of the engaging prongs 15a and 15b (or 32a and 32b) of the hook 10 (or eye 30) come into surface contact across the fabric 110 with the relevant retainer 20 (or 40) and the flat parts 16a and 16b (or 33a and 33b) at the leading ends of the engaging prongs 15a and 15b (or 32a and 32b) in the state described above are forced through the thin-wall parts 24a and 24b (or 44a and 44b) of the retainer 20 (or 40). At the time that the engaging prongs 15a and 15b (or 32a and 32b) of the hook 10 (or eye 30) pierce the thin-wall parts 24a and 24b (or 44a and 44b) of the retainer 20 (or 40), therefore, the fabric 110 is cut in the plane or line of contact between the flat parts 16a and 16b (or 33a and 33b) or edges thereof at the leading ends of the engaging prongs 15a and 15b (or 32a and 32b) and the thin-wall parts 24a and 24b (or 44a and 44b) of the retainer 20 (or 40). Subsequently, when the engaging prongs 15a and 15b (or 32a and 32b) are to be inserted into the through holes formed in the thin-wall parts 24a and 24b (or 44a and 44b) by the engaging prongs 15a and 15b (or 32a and 32b), the leading ends of the engaging prongs 15a and 15b (or 32a and 32b) neither catch hold of threads of the fabric 110 and drag them into the through holes nor impart wrinkles to the fabric 110. The attachment of the hook-and-eye fastener to the fabric, therefore, can be attained infallibly without imparting wrinkles to the fabric even when the fabric is made of threads of silk or the so-called new synthetic fibers which have a particularly small diameter. Since in the aforementioned embodiment the retainers 20 and 40 are made of aluminum, the retainers 20 and 40 themselves and the thin-wall parts 24a, 24b, 44a and 44b thereof can be easily formed. Further, the engaging prongs 15a, 15b, 32a and 32b of the hook 10 and the eye 30 having the flat parts 16a, 16b, 33a and 33b at the leading ends thereof are allowed to pierce the thin-wall parts 24a, 24b, 44a and 44b of the retainers 20 and 40 with ease. The hook-and-eye fastener is possessed of ample strength. The invention may be embodied in other specific forms without departing from the essential characteristics thereof, as defined by the claims. For instance, the engaging prongs 15a, 15b, 32a and 32b of the hook-and-eye fastener of the present invention are only required to be so shaped as to have flat parts 16a, 16b, 33a and 33b at the leading ends thereof. The area and shape of these flat parts may be freely set so as to fit the material and thickness of the fabric 110 and the purpose for which the hook-and-eye fastener is to be used. The upwardly bent rear portion 22 of the retainer 20 may have a free end lying flush with the upper surface of the central raised portion 21 so that the free end of the upwardly bent rear portion 22 and the central raised portion 21 sufficiently bite into the garment fabric 110 to prevent any relative movement between the retainer 20 and the fabric 110. Similarly, the upwardly bent portions 42 and 43 of the retainer 40 for the eye 30 may have a free end lying flush with the upper surface of the central raised portion 41. The described embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by foregoing description and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

Claims: A hook (10) for a hook-and-eye fastener (1), comprising: a pair of engaging prongs (15a, 15b) projecting substantially perpendicularly therefrom; and a retainer (20) adapted to immobilize the hook (10) and intended to be disposed on the side of a fabric (110) opposite to the side thereof on which the hook (10) is set in place; the retainer (20) having a pair of thin-wall parts (24a, 24b) adapted to be pierced by the pair of engaging prongs (15a, 15b) of the hook (10), characterised in that leading ends of the engaging prongs (15a, 15b) of the hook (10) are formed in the shape of a flat part (16a, 16b) lying in a plane substantially perpendicular to a direction of penetration of the engaging prongs (15a, 15b) into the thin-wall parts (24a, 24b) of the retainer (20). The hook (10) of claim 1, characterised in that the hook (10) is made of metal and the retainer (20) is made of aluminum or aluminum alloy. The hook (10) of claim 1 or 2, characterised in that each of the engaging prongs (15a, 15b) of the hook has a free end part configured as a truncated wedge. The hook (10) of claim 1 or 2 in combination with claim 3, characterised in that the hook (10) has a one-piece body including a base (13), a locking tongue (11) lying substantially parallel to the base (13), and an intermediate arcuate portion (12) extending between the base (13) and the locking tongue so as to define therebetween an eye receiving channel, the base having on opposite lateral edges thereof the pair of engaging prongs (15a, 15b) projecting substantially perpendicularly therefrom in a direction away from the locking tongue (11). The hook (10) of any of claims 1 to 4, characterised in that each thin-wall part (24a, 24b) of the retainer (20) has an upper surface lying flush with an upper surface of the retainer (20) and a lower concave surface. The hook (10) of any of claims 1, 2 or 5 in combination with claims 3 and 4, characterised in that the leading end face of the truncated wedge is formed in a flat surface substantially perpendicular to a longitudinal direction thereof. An eye (30) for a hook-and-eye fastener (1), comprising: a pair of engaging prongs (32a, 32b) projecting substantially perpendicularly therefrom; and a retainer (40) adapted to immobilize the eye (30) and intended to be disposed on the side of a fabric (110) opposite to the side thereof on which the eye (30) is set in place; the retainer (40) having a pair of thin-wall parts (44a, 44b) adapted to be pierced by the pair of engaging prongs (32a, 32b) of the eye (30), characterised in that leading ends of the engaging prongs (32a, 32b) of the eye (30) are formed in the shape of a flat part (33a, 33b) lying in a plane substantially perpendicular to a direction of penetration of the engaging prongs (32a, 32b) into the thin-wall parts (44a, 44b) of the retainer (40). The eye (30) of claim 7, characterised in that the eye (30) is made of metal and the retainer (40) is made of aluminum or aluminum alloy. The eye (30) of claim 7 or 8, characterised in that each of the engaging prongs (32a, 32b) of the eye has a free end part configured as a truncated wedge. The eye (30) of any of claims 7 to 9, characterised in that the eye (30) includes an upper plate, the pair of engaging prongs (32a, 32b) projecting substantially perpendicularly from opposite lateral edges thereof. The eye (30) of any of claims 7 to 10, characterised in that each thin-wall part (44a, 44b) of the eye retainer (40) has an upper surface lying flush with an upper surface of the retainer (40) and a lower concave surface. The eye (30) of any of claims 7, 8 or 11 in combination with claims 9 and 10, characterised in that the leading end face of the truncated wedge is formed in a flat surface substantially perpendicular to a longitudinal direction thereof. A hook-and-eye fastener (1), characterised in that it comprises a hook (10) having the features of any of claims 1 to 6 and an eye (30) having the features of any of claims 7 to 12.

Inventors: FUKUSHIMA JUKICHI, FUKUSHIMA, JUKICHI
Applicants: YKK CORP, YKK CORPORATION
Application year: 1994
Main classification: A44B13
IPC codes: A44B13